1. Field of the Invention
The present invention relates to a driving circuit of a plasma display panel and a plasma display panel.
2. Description of the Related Art
FIG. 25 is a diagram showing the basic configuration of a plasma display device. A control circuit section 1101 controls an address driver 1102, a sustain electrode (X electrode) sustain (sustain discharge) circuit 1103, a scan electrode (Y electrode) sustain circuit 1104, and a scan driver 1105.
The address driver 1102 supplies a predetermined voltage to address electrodes A1, A2, A3, . . . Hereafter, each of the address electrodes A1, A2, A3, . . . or their generic name is an address electrode Aj, j representing a suffix.
The scan driver 1105 supplies a predetermined voltage to scan electrodes Y1, Y2, Y3, . . . in accordance with control of the control circuit section 1101 and the scan electrode sustain circuit 1104. Hereafter, each of the scan electrodes Y1, Y2, Y3, . . . or their generic name is a scan electrode Yi, i representing a suffix.
The sustain electrode sustain circuit 1103 supplies the same voltage to sustain electrodes X1, X2, X3, . . . respectively. Hereafter, each of the sustain electrodes X1, X2, X3, . . . or their generic name is a sustain electrode Xi, i representing a suffix. The sustain electrodes Xi are connected to each other and have the same voltage level.
Within a display region 1107, the scan electrodes Yi and the sustain electrodes Xi form rows extending in parallel in the horizontal direction, and the address electrodes Aj form columns extending in the vertical direction. The scan electrodes Yi and the sustain electrodes Xi are alternately arranged in the vertical direction. Ribs 1106 have a stripe rib structure provided between the address electrodes Aj.
The scan electrodes Yi and the address electrodes Aj form a two-dimensional matrix with i rows and j columns. A display cell Cij is formed of an intersection of the scan electrode Yi and the address electrode Aj and the sustain electrode Xi correspondingly adjacent thereto. This display cell Cij corresponds to a pixel, so that the display region 1107 can display a two-dimensional image.
FIG. 26A is a view showing the configuration of a cross section of the display cell Cij in FIG. 25. The sustain electrode Xi and the scan electrode Yi are formed on a front glass substrate 1211. A dielectric layer 1212 for insulating the electrodes from a discharge space 1217 is applied thereover, and a MgO (magnesium oxide) protective film 1213 is further applied over the dielectric layer 1212.
On the other hand, the address electrode Aj is formed on a rear glass substrate 1214 which is disposed to oppose the front glass substrate 1211, a dielectric layer 1215 is applied thereover, and further phosphors are applied over the dielectric layer 1215. In the discharge space 1217 between the MgO protective film 1213 and the dielectric layer 1215, a Ne+Xe Penning gas or the like is sealed.
FIG. 26B is a view for explaining a capacitance Cp of an AC drive type plasma display. A capacitance Ca is a capacitance of the discharge space 1217 between the sustain electrode Xi and the scan electrode Yi. A capacitance Cb is a capacitance of the dielectric layer 1212 between the sustain electrode Xi and the scan electrode Yi. A capacitance Cc is a capacitance of the front glass substrate 1211 between the sustain electrode Xi and the scan electrode Yi. The sum of the capacitances Ca, Cb, and Cc determines the capacitance between the electrodes Xi and Yi.
FIG. 26C is a view for explaining light emission of the AC drive type plasma display. On an inner surface of a rib 1216, phosphors 1218 in red, blue and green are applied, arranged in stripes for each color, so that a discharge between the sustain electrode Xi and the scan electrode Yi excites the phosphors 1218 to generate light 1221.
FIG. 27 is a diagram of the configuration of one frame FR of an image. The image is formed of, for example, 60 frames per second. One frame FR is formed of a first subframe SF1, a second subframe SF2, . . . , and an nth subframe SFn. This n is, for example, 10, and corresponds to the number of grayscale bits. Each of the subframes SF1, SF2, and so on or their generic name is a subframe SF hereafter.
Each subframe SF is composed of a reset period Tr, an address period Ta, and a sustain period (sustain discharge period) Ts. During the rest period Tr, the display cell is initialized. During the address period Ta, lighting or non-lighting of each display cell can be selected by addressing. The selected cell emits light during the sustain period Ts. The number of light emissions (period of time) is different in each SF. This can determine a grayscale value.
FIG. 28 shows a driving method during the sustain period Ts of a progressive method plasma display according to the prior art. At time t1, an anode potential Vs1 is applied to the sustain electrodes Xn−1, Xn, and Xn+1, and a cathode potential Vs2 is applied to the scan electrodes Yn−1, Yn, and Yn+1. This applies a high voltage respectively between the sustain electrode Xn−1 and the scan electrode Yn−1, between the sustain electrode Xn and the scan electrode Yn, and between the sustain electrode Xn+1 and the scan electrode Yn+1 to perform sustain discharges 1410.
Subsequently, at time t2, the cathode potential Vs2 is applied to the sustain electrodes Xn−1, Xn, and Xn+1, and the anode potential Vs1 is applied to the scan electrodes Yn−1, Yn, and Yn+1. This applies a high voltage respectively between the sustain electrode Xn−1 and the scan electrode Yn−1, between the sustain electrode Xn and the scan electrode Yn, and between the sustain electrode Xn+1 and the scan electrode Yn+1 to perform sustain discharges 1410.
Subsequently, at time t3, the same potentials as those at time t1 are applied to perform sustain discharges 1410, and at time t4, the same potentials as those at time t2 are applied to perform sustain discharges 1410.
FIG. 29 shows a driving method during the sustain period Ts of a plasma display by an ALIS (Alternate Lighting of Surfaces) method according to the prior art. At time t1, the anode potential Vs1 is applied to the sustain electrodes Xn−1 and Xn+1 on odd-numbered rows, and the cathode potential Vs2 is applied to the scan electrodes Yn−1 and Yn+1 on odd-numbered rows. Further, the cathode potential Vs2 is applied to the sustain electrode Xn on an even-numbered row, and the anode potential Vs1 is applied to the scan electrode Yn on an even-numbered row. This applies a high voltage respectively between the sustain electrode Xn−1 and the scan electrode Yn−1, between the sustain electrode Xn and the scan electrode Yn, and between the sustain electrode Xn+1 and the scan electrode Yn+1 to perform sustain discharges 1510.
Subsequently, at time t2, the cathode potential Vs2 is applied to the sustain electrodes Xn−1 and Xn+1 on the odd-numbered rows, and the anode potential Vs1 is applied to the scan electrodes Yn−1 and Yn+1 on the odd-numbered rows. Further, the anode potential Vs1 is applied to the sustain electrode Xn on the even-numbered row, and the cathode potential Vs2 is applied to the scan electrode Yn on the even-numbered row. This applies a high voltage respectively between the sustain electrode Xn−1 and the scan electrode Yn−1, between the sustain electrode Xn and the scan electrode Yn, and between the sustain electrode Xn+1 and the scan electrode Yn+1 to perform sustain discharges 1510.
Subsequently, at time t3, the same potentials as those at time t1 are applied to perform sustain discharges 1510, and at time t4, the same potentials as those at time t2 are applied to perform sustain discharges 1510.
With an increase in resolution of plasma displays, the distance between adjacent electrodes decreases. This results in shortened distances from the sustain electrode Xn and the scan electrode Yn constituting the discharge space to the scan electrode Yn−1 and the sustain electrode Xn+1 arranged adjacent thereto, respectively.
Therefore, when a discharge is caused between the sustain electrode Xn and the scan electrode Yn, electrons on the scan electrode Yn−1 or the sustain electrode Xn+1 are likely to diffuse (transfer) to cause an adjacent display cell constituted of the sustain electrode Xn−1 and the scan electrode Yn−1 or the sustain electrode Xn+1 and the scan electrode Yn+1 to perform error display such that the display cell lights up during time when the display cell should turn off, or the display cell turns off during time when the display cell should light up because the electrodes cannot sustain a discharge.